This is a super simple way to create low fidelity multiples for prototyping purposes.
Step 1: Choose & Mark Material: Cut to Square
I chose some cheap construction grade pine for this exercise. I'll be making 3 wheels for part of a chair mock-up.
Measure and cut squares; make a corner to corner 'X' to find the center on both sides.
Step 2: Round off Squares
Now, use a compass to mark the same size circle form the center of each square.
Use a band saw to cut as close to circular as possible. Keep in mind that slightly over size is better than under.
Step 3: Set Up Lathe: First Piece
Set up your lathe and material, making sure to follow all the procedures from TechShop's Safety and Basic Use class.
Smooth off the outside and face surfaces of your wheel. You want to get it uniform and flat, maintaining the desired dimensions you want for the rest of the pieces.
Note that I lifted the guard up only to take photos.
Step 4: Make your Template
I used cardboard, a utility knife and a sharpie, but you could take this idea up a notch and cut a nice template on the laser once you're ready for a more refined design.
The most important thing is that the template wraps around two faces of the form, so you have something you're measuring off of.
If you're having trouble picturing what your shape will look like, try making some different 'revolves' in Autodesk Inventor. You can then laser cut the profiles you like as templates to try.
Step 5: Mark Key Template Points on the Wheel
Now, hold your template up to the wheel (while the lathe is stopped) and mark the key points where the form changes. Your marks will need to be robust enough to be visible while the lathe is spinning.
Once you have the first marks, turn on the lathe and touch them with your sharpie to make them more visible.
Start shaping the wheel and every once in a while, check your progress with the template. I used the same template on both sides of these wheels, so in essence it was six repetitions.
Step 7: Rinse and Repeat!
Re-use your template to create as many as you need, quickly and simply!